summaryrefslogtreecommitdiff
path: root/fs/btrfs/transaction.c
AgeCommit message (Collapse)Author
2018-03-31btrfs: Remove btrfs_fs_info::open_ioctl_transNikolay Borisov
Since userspace transaction have been removed we no longer have use for this field so delete it. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-31btrfs: Remove code referencing unused TRANS_USERSPACENikolay Borisov
Now that the userspace transaction ioctls have been removed, TRANS_USERSPACE is no longer used hence we can remove it. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-31btrfs: qgroup: Fix root item corruption when multiple same source snapshots ↵Qu Wenruo
are created with quota enabled When multiple pending snapshots referring to the same source subvolume are executed, enabled quota will cause root item corruption, where root items are using old bytenr (no backref in extent tree). This can be triggered by fstests btrfs/152. The cause is when source subvolume is still dirty, extra commit (simplied transaction commit) of qgroup_account_snapshot() can skip dirty roots not recorded in current transaction, making root item of source subvolume not updated. Fix it by forcing recording source subvolume in current transaction before qgroup sub-transaction commit. Reported-by: Justin Maggard <jmaggard@netgear.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Move error handling of btrfs_start_dirty_block_groups closer to call siteNikolay Borisov
Even though btrfs_start_dirty_block_groups is fairly in the beginning of btrfs_commit_transaction outside of the critical section defined by the transaction states it can only be run by a single comitter. In other words it defines its own critical section thanks to the BTRFS_TRANS_DIRTY_BG run flag and ro_block_group_mutex. However, its error handling is outside of this critical section which is a bit counter-intuitive. So move the error handling righ after the function is executed and let the sole runner of dirty block groups handle the return value. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove fs_info argument of btrfs_write_and_wait_transactionNikolay Borisov
We already pass btrfs_trans_handle which contains a reference to the fs_info so use that. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove fs_info argument from btrfs_update_commit_device_bytes_usedNikolay Borisov
We already pass the btrfs_transaction which references fs_info so no need to pass the later as an argument. Also use the opportunity to shorten transaction->trans. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove fs_info argument from ↵Nikolay Borisov
create_pending_snapshots/create_pending_snapshot We already pass the trans handle which has a reference to fs_info to create_pending_snapshot so we can refer to it directly. Doing this obviates the need to pass the fs_info to create_pending_snapshots as well. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove fs_info argument from switch_commit_rootsNikolay Borisov
We already have the fs_info from the passed transaction so use it directly. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove root argument of cleanup_transactionNikolay Borisov
The only thing the passed root is used for is: 1. get a reference to the fs_info and to 2. call trace_btrfs_transaction_commit. We can achieve 1) by simply referring to the fs_info from passed trans object. As far as 2) is concerned cleanup_transaction is called from only one place and the 'root' argument passed is the one from the trans handle. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Don't pass fs_info to commit_cowonly_rootsNikolay Borisov
We already pass a transaction handle which refrences the fs_info so we can grab it from there. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Don't pass fs_info to commit_fs_rootsNikolay Borisov
We already pass the transaction handle which has a reference to the fs_info. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Don't pass fs_info to btrfs_run_delayed_items/_nrNikolay Borisov
We already pass the transaction which has a reference to the fs_info, so use that. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Don't pass fs_info arg to btrfs_start_dirty_block_groupsNikolay Borisov
It can be referenced from the passed transaction so no point in passing it as a function argument. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove fs_info argument from btrfs_create_pending_block_groupsNikolay Borisov
It can be referenced from the passed transaciton so no point in passing it as function argument. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove fs_info argument from btrfs_trans_release_metadataNikolay Borisov
All current callers of this function just get a reference to the trans->fs_info member and pass it as the second argument. Collapse this into the function itself. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Open code btrfs_write_and_wait_marked_extentsNikolay Borisov
btrfs_write_and_wait_transaction is essentially a wrapper of btrfs_write_and_wait_marked_extents with the addition of calling clear_btree_io_tree. Having the code split doesn't really bring any benefit. Open code the later into the former and add proper documentation header. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ reformat comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Make btrfs_trans_release_metadata private to transaction.cNikolay Borisov
This function is only ever used in __btrfs_end_transaction and btrfs_commit_transaction so there is no need to export it via header. Let's move it closer to where it's used, make it static and remove it from the header. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: Remove unused btrfs_start_transaction_lflush functionNikolay Borisov
Commit 0e8c36a9fd81 ("Btrfs: fix lots of orphan inodes when the space is not enough") changed the way transaction reservation is made in btrfs_evict_node and as a result this function became unused. This has been the status quo for 5 years in which time no one noticed, so I'd say it's safe to assume it's unlikely it will ever be used again. Historical note: there were more attempts to remove the function, the reasoning was missing and only based on some static analysis tool reports. Other reason for rejection was that there seemed to be connection to BTRFS_RESERVE_FLUSH_LIMIT and that would need to be removeed to. This was not correct so removing the function is all we can do. Signed-off-by: Nikolay Borisov <nborisov@suse.com> [ add the note ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-16Revert "btrfs: use proper endianness accessors for super_copy"David Sterba
This reverts commit 3c181c12c431fe33b669410d663beb9cceefcd1b. The offending patch was merged in 4.16-rc4 and was promptly applied to stable kernels 4.14.25 and 4.15.8. The patch causes a corruption in several superblock items on big-endian machines because of messed up endianity conversions. The damage is manually repairable. A filesystem cannot be mounted again after it has been unmounted once. We do a full revert and not a fixup so stable can pick that patch ASAP. Fixes: 3c181c12c431 ("btrfs: use proper endianness accessors for super_copy") Link: https://lkml.kernel.org/r/1521139304@msgid.manchmal.in-ulm.de CC: stable@vger.kernel.org # 4.14+ Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01btrfs: use proper endianness accessors for super_copyAnand Jain
The fs_info::super_copy is a byte copy of the on-disk structure and all members must use the accessor macros/functions to obtain the right value. This was missing in update_super_roots and in sysfs readers. Moving between opposite endianness hosts will report bogus numbers in sysfs, and mount may fail as the root will not be restored correctly. If the filesystem is always used on a same endian host, this will not be a problem. Fix this by using the btrfs_set_super...() functions to set fs_info::super_copy values, and for the sysfs, use the cached fs_info::nodesize/sectorsize values. CC: stable@vger.kernel.org Fixes: df93589a17378 ("btrfs: export more from FS_INFO to sysfs") Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: simplify mutex unlocking code in btrfs_commit_transactionAnand Jain
No functional change rearrange the mutex_unlock. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> [ edit subject ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: switch to refcount_t type for btrfs_trans_handle::use_countDavid Sterba
The use_count is a reference counter, we can use the refcount_t type, though we don't use the atomicity. This is not a performance critical code and we could catch the underflows. The type is changed from long, but the number of references will fit an int. Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: sink gfp parameter to clear_extent_bitDavid Sterba
All callers use GFP_NOFS, we don't have to pass it as an argument. The built-in tests pass GFP_KERNEL, but they run only at module load time and NOFS works there as well. Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01btrfs: don't call btrfs_start_delalloc_roots in flushoncommitJosef Bacik
We're holding the sb_start_intwrite lock at this point, and doing async filemap_flush of the inodes will result in a deadlock if we freeze the fs during this operation. This is because we could do a btrfs_join_transaction() in the thread we are waiting on which would block at sb_start_intwrite, and thus deadlock. Using writeback_inodes_sb() side steps the problem by not introducing all of these extra locking dependencies. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30Btrfs: only check delayed ref usage in should_end_transactionJosef Bacik
We were only doing btrfs_check_space_for_delayed_refs() if the metadata space was full, ie we couldn't allocate chunks. This assumes we'll be able to allocate chunks during transaction commit, but since nothing does a LIMIT flush during the transaction commit this won't actually happen unless we happen to run shy of actual space. We already take into account a full fs in btrfs_check_space_for_delayed_refs() so just kill this extra check to make sure we're ending the transaction when we need to. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30Btrfs: make plug in writing meta blocks really workLiu Bo
We have started plug in btrfs_write_and_wait_marked_extents() but the generated IOs actually go to device's schedule IO list where the work is doing in another task, thus the started plug doesn't make any sense. And since we wait for IOs immediately after writing meta blocks, it's the same case as writing log tree, doing sync submit can merge more IOs. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29btrfs: fix integer overflow in calc_reclaim_items_nrChris Mason
Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with v4.12-rc6. This was because commit 70e7af244 made it possible for calc_reclaim_items_nr() to return a negative number. It's not really a bug in that commit, it just didn't go far enough down the stack to find all the possible 64->32 bit overflows. This switches calc_reclaim_items_nr() to return a u64 and changes everyone that uses the results of that math to u64 as well. Reported-by: Dave Jones <davej@codemonkey.org.uk> Fixes: 70e7af2 ("Btrfs: fix delalloc accounting leak caused by u32 overflow") Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29btrfs: qgroup: Cleanup btrfs_qgroup_prepare_account_extents functionQu Wenruo
Quite a lot of qgroup corruption happens due to wrong time of calling btrfs_qgroup_prepare_account_extents(). Since the safest time is to call it just before btrfs_qgroup_account_extents(), there is no need to separate these 2 functions. Merging them will make code cleaner and less bug prone. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog and comment adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-20btrfs: move fs_info::fs_frozen to the flagsDavid Sterba
We can keep the state among the other fs_info flags, there's no reason why fs_frozen would need to be separate. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19btrfs: use generic slab for for btrfs_transactionDavid Sterba
Observing the number of slab objects of btrfs_transaction, there's just one active on an almost quiescent filesystem, and the number of objects goes to about ten when sync is in progress. Then the nubmer goes down to 1. This matches the expectations of the transaction lifetime. For such use the separate slab cache is not justified, as we do not reuse objects frequently. For the shortlived transaction, the generic slab (size 512) should be ok. We can optimistically expect that the 512 slabs are not all used (fragmentation) and there are free slots to take when we do the allocation, compared to potentially allocating a whole new page for the separate slab. We'll lose the stats about the object use, which could be added later if we really need them. Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19Btrfs: replace tree->mapping with tree->private_dataJosef Bacik
For extent_io tree's we have carried the address_mapping of the inode around in the io tree in order to pull the inode back out for calling into various tree ops hooks. This works fine when everything that has an extent_io_tree has an inode. But we are going to remove the btree_inode, so we need to change this. Instead just have a generic void * for private data that we can initialize with, and have all the tree ops use that instead. This had a lot of cascading changes but should be relatively straightforward. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Reviewed-by: David Sterba <dsterba@suse.com> [ minor reordering of the callback prototypes ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: qgroup: Fix qgroup corruption caused by inode_cache mount optionQu Wenruo
[BUG] The easist way to reproduce the bug is: ------ # mkfs.btrfs -f $dev -n 16K # mount $dev $mnt -o inode_cache # btrfs quota enable $mnt # btrfs quota rescan -w $mnt # btrfs qgroup show $mnt qgroupid rfer excl -------- ---- ---- 0/5 32.00KiB 32.00KiB ^^ Twice the correct value ------ And fstests/btrfs qgroup test group can easily detect them with inode_cache mount option. Although some of them are false alerts since old test cases are using fixed golden output. While new test cases will use "btrfs check" to detect qgroup mismatch. [CAUSE] Inode_cache mount option will make commit_fs_roots() to call btrfs_save_ino_cache() to update fs/subvol trees, and generate new delayed refs. However we call btrfs_qgroup_prepare_account_extents() too early, before commit_fs_roots(). This makes the "old_roots" for newly generated extents are always NULL. For freeing extent case, this makes both new_roots and old_roots to be empty, while correct old_roots should not be empty. This causing qgroup numbers not decreased correctly. [FIX] Modify the timing of calling btrfs_qgroup_prepare_account_extents() to just before btrfs_qgroup_account_extents(), and add needed delayed_refs handler. So qgroup can handle inode_map mount options correctly. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: remove unused qgroup members from btrfs_trans_handleDavid Sterba
The members have been effectively unused since "Btrfs: rework qgroup accounting" (fcebe4562dec83b3), there's no substitute for assert_qgroups_uptodate so it's removed as well. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_transaction.use_count from atomic_t to refcount_tElena Reshetova
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28btrfs: Make btrfs_i_size_write take btrfs_inodeNikolay Borisov
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28btrfs: Make btrfs_set_inode_index take btrfs_inodeNikolay Borisov
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28btrfs: Make btrfs_insert_dir_item take btrfs_inodeNikolay Borisov
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: remove unused parameter from btrfs_prepare_extent_commitDavid Sterba
Added but never used. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: merge two superblock writing helpersDavid Sterba
write_all_supers and write_ctree_super are almost equal, the parameter 'trans' is unused so we can drop it and have just one helper. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-17btrfs: remove unnecessary mutex lock in qgroup_account_snapshotDavid Sterba
The quota status used to be tracked as a variable, so the mutex was needed (until "Btrfs: add a flags field to btrfs_fs_info" afcdd129e05a9). Since the status is a bit modified atomically and we don't hold the mutex beyond the check, we can drop it. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14btrfs: allow unlink to exceed subvolume quotaJeff Mahoney
Once a qgroup limit is exceeded, it's impossible to restore normal operation to the subvolume without modifying the limit or removing the subvolume. This is a surprising situation for many users used to the typical workflow with quotas on other file systems where it's possible to remove files until the used space is back under the limit. When we go to unlink a file and start the transaction, we'll hit the qgroup limit while trying to reserve space for the items we'll modify while removing the file. We discussed last month how best to handle this situation and agreed that there is no perfect solution. The best principle-of-least-surprise solution is to handle it similarly to how we already handle ENOSPC when unlinking, which is to allow the operation to succeed with the expectation that it will ultimately release space under most circumstances. This patch modifies the transaction start path to select whether to honor the qgroups limits. btrfs_start_transaction_fallback_global_rsv is the only caller that skips enforcement. The reservation and tracking still happens normally -- it just skips the enforcement step. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14btrfs: Make btrfs_ino take a struct btrfs_inodeNikolay Borisov
Currently btrfs_ino takes a struct inode and this causes a lot of internal btrfs functions which consume this ino to take a VFS inode, rather than btrfs' own struct btrfs_inode. In order to fix this "leak" of VFS structs into the internals of btrfs first it's necessary to eliminate all uses of struct inode for the purpose of inode. This patch does that by using BTRFS_I to convert an inode to btrfs_inode. With this problem eliminated subsequent patches will start eliminating the passing of struct inode altogether, eventually resulting in a lot cleaner code. Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> [ fix btrfs_get_extent tracepoint prototype ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14Btrfs: ACCESS_ONCE cleanupSeraphime Kirkovski
This replaces ACCESS_ONCE macro with the corresponding READ|WRITE macros Signed-off-by: Seraphime Kirkovski <kirkseraph@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: remove root parameter from transaction commit/end routinesJeff Mahoney
Now we only use the root parameter to print the root objectid in a tracepoint. We can use the root parameter from the transaction handle for that. It's also used to join the transaction with async commits, so we remove the comment that it's just for checking. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: split btrfs_wait_marked_extents into normal and tree log functionsJeff Mahoney
btrfs_write_and_wait_marked_extents and btrfs_sync_log both call btrfs_wait_marked_extents, which provides a core loop and then handles errors differently based on whether it's it's a log root or not. This means that btrfs_write_and_wait_marked_extents needs to take a root because btrfs_wait_marked_extents requires one, even though it's only used to determine whether the root is a log root. The log root code won't ever call into the transaction commit code using a log root, so we can factor out the core loop and provide the error handling appropriate to each waiter in new routines. This allows us to eventually remove the root argument from btrfs_commit_transaction, and as a result, btrfs_end_transaction. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: take an fs_info directly when the root is not used otherwiseJeff Mahoney
There are loads of functions in btrfs that accept a root parameter but only use it to obtain an fs_info pointer. Let's convert those to just accept an fs_info pointer directly. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: root->fs_info cleanup, access fs_info->delayed_root directlyJeff Mahoney
This results in btrfs_assert_delayed_root_empty and btrfs_destroy_delayed_inode taking an fs_info instead of a root. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: root->fs_info cleanup, add fs_info convenience variablesJeff Mahoney
In routines where someptr->fs_info is referenced multiple times, we introduce a convenience variable. This makes the code considerably more readable. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: root->fs_info cleanup, btrfs_calc_{trans,trunc}_metadata_sizeJeff Mahoney
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: pull node/sector/stripe sizes out of root and into fs_infoJeff Mahoney
We track the node sizes per-root, but they never vary from the values in the superblock. This patch messes with the 80-column style a bit, but subsequent patches to factor out root->fs_info into a convenience variable fix it up again. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>